1. Field of the Invention
The present invention relates to improvements in metal clinching devices, having as their purpose the fastening of two contiguous sheets of metal by piercing and tearing the metal flanges so as to form tabs which are then folded back against the flanges to secure the flanges together.
2. Description of the Prior Art
Clinching mechanisms of the general type to which the present invention pertains have been under a constant state of development as far back as 1932 and even though spot welding and pop rivet techniques are in current wide use, there is a continuing need for a fast, efficient and inexpensive means of fastening contiguous sheet metal members together along a flange of seam particularly in products where space limitations may make other means impractical. Among those who have attempted to devise tools of the type to which the present invention pertains include R. H. Spingler, et al., U.S. Pat. No. 2,964,829 and somewhat later effort by K. J. Klenk, U.S. Pat. No. 3,261,073. While all of these patent efforts have a comparable purpose, each provides a different, and more cumbersome, approach to the problem and each, for many reasons, fails to provide the handling and efficiency of the present device.